1. Field of the Invention
The present invention relates to a developing device provided in an image forming apparatus such as an electrostatic copying machine, printer, facsimile machine, or a composite of these, and to an image forming apparatus having the developing device.
2. Description of the Related Art
There is known a developing device in which a magnetic roller (developer bearing member) which holds and conveys a two-component developer consisting of a magnetic carrier and a non-magnetic toner on a circumferential surface of the roller, and a developing roller (toner bearing member) which is disposed so as to oppose the magnetic roller, are supported rotatably inside a developing housing having a developer accommodating chamber. In this developing device, toner in a developer which has been supplied from the developer accommodating chamber and is held on the magnetic roller adheres electrostatically to the developing roller.
In this developing device, the magnetic roller is disposed obliquely below and to the right of the developing roller. The developer accommodating chamber includes a pair of agitating and conveying members which are disposed in parallel fashion in the lateral direction, at positions vertically below the positions where the developing roller and the magnetic roller are disposed (positions included in the downward projected regions of the rollers). Furthermore, a recovery roller is disposed so as to make contact with the lower end portion of the surface of the developing roller.
In the developing device described above, undeveloped toner (residual toner) which is remaining on the surface of the developing roller is scraped off and recovered by means of the recovery roller. On the other hand, toner (residual toner) which has not been supplied from the magnetic roller to the developing roller drops down naturally into the separating magnetic pole region of the magnetic roller and is recovered into the developer accommodating chamber. Furthermore, dispersed toner also drops down inside the developer accommodating chamber and is thereby recovered.
However, due to the layout of the developing device, there are cases where the developer accommodating chamber is not disposed in a position vertically below the positions where the magnetic roller and the developing roller are disposed, but rather is disposed in a position shifted in the lateral direction or in an upper position, or the like. In this case, it becomes difficult to recover residual toner from the developing roller and the magnetic roller, or to dispersed toner.